Nuclear weapon effect question

Post by **Sea Skimmer** » 2003-05-03 11:38am

Someone wouldn't happen to have a formal to tell me what depth I'd need to bury a 400 megaton nuke to contain the fireball now would they?

Admiral Valdemar · Post by **Admiral Valdemar** » 2003-05-03 11:45am

400 what? Kilotons?

Post by **Sea Skimmer** » 2003-05-03 12:08pm

Opps, should be 400 megatons.

Admiral Valdemar · Post by **Admiral Valdemar** » 2003-05-03 12:10pm

Sea Skimmer wrote:Opps, should be 400 megatons.

Geebus, what're going to do with that?!

I'd say a fair few hundred klicks to totally contain that blast and not have the surface notice much other than tremors, but I'm no geologist.

JodoForce · Post by **JodoForce** » 2003-05-03 12:27pm

Ask the French, maybe?

Nathan F · Post by **Nathan F** » 2003-05-03 12:29pm

400 MEGAton?

You would have to bury that sucker DEEP, and it would probably be so deep and so powerful of a blast, that it would start triggering earthquakes on fault lines and create serious geological damage.

Sokar · Post by **Sokar** » 2003-05-03 01:13pm

Jesus Skimmer

The Soviets had to bury the 56 megaton bomb they tested in the mids 80's a 3/4 a mile down, and it still sank three square miles of the island Novoya Zelemya when they popped it.

400 Megatons, you'd need to sink it miles into solid granite to contain it , and your still going to shatter a good chunk of it into gravel when that bastard blows.

Out of curiosity what are you planning to obliterate?

Burak Gazan · Post by **Burak Gazan** » 2003-05-03 01:17pm

You might not be able to bury it deep enough with a weapon that size. The shaft would be likely kilometres deep, and to get deep enough to contain the fireball, might push technology past the limit

Plus, since such a weapon does not and has not ever existed, you gotta come up with a completely new weapon design

Sure as hell wouldn't want to surface-detonate or even airburst it, the fallout from such a device would be off the scale

Be a three-stager for sure, and probably not vey portable

Post by **Sea Skimmer** » 2003-05-03 01:26pm

You people are confusing the distances needed to totally contain a blast and avoid releasing radioactivity with those needed simply to contain the fireball, I don't care if a lot of earth still goes up in the air in a mushroom cloud and the whole area is coated in fall out.

As for what I want it for, it just happens to be a yield of several earth penetrating anti bunker weapons I'm using in various sci fi contexts. I'm just looking for a better idea of how deep it should burrow.

The Russians have already built massive bunkers covering about 400 square kilometers, and we have gold mines sinking down a couple kilometers. This weapon would be able to largely destroy something with both features and with sci tech materials for reinforcement.

Post by **Sea Skimmer** » 2003-05-03 01:31pm

Sokar wrote:Jesus Skimmer The Soviets had to bury the 56 megaton bomb they tested in the mids 80's a 3/4 a mile down, and it still sank three square miles of the island Novoya Zelemya when they popped it.

The Soviets tested a 50-60 megaton bomb in the 1950's over Novoya Zelemya, however it was a high airburst and didn't even have much of crater. Some of the US's early thermonuke tests wiped out very small islands in the pacific and blew huge holes in reefs but there was never any case of multipul sqaure miles falling into the sea in US or Russian tests.

Einhander Sn0m4n · Post by **Einhander Sn0m4n** » 2003-05-03 01:35pm

Sea Skimmer wrote:You people are confusing the distances needed to totally contain a blast and avoid releasing radioactivity with those needed simply to contain the fireball, I don't care if a lot of earth still goes up in the air in a mushroom cloud and the whole area is coated in fall out.

As for what I want it for, it just happens to be a yield of several earth penetrating anti bunker weapons I'm using in various sci fi contexts. I'm just looking for a better idea of how deep I should burrow it for the effect I want.

So basically you're looking for something a bit like the Sedan Test?

http://www.calguard.ca.gov/ia/Nukes/XX1 ... -blast.jpg <== I will NOT inline that pic, it's fucking HUGE!!!

http://www.fas.org/irp/imint/doe_nts_nf121.htm

Post by **Sea Skimmer** » 2003-05-03 01:42pm

Yes that would be the kind of surface effect I'm looking for. I highly doubt anyone actually has the formal or rules of thumb I'm looking for, if they exist. But it's seems worth a shot.

Post by **Sea Skimmer** » 2003-05-03 01:47pm

JodoForce wrote:Ask the French, maybe?

I don't think France ever tested anything over one or two megatons. Hell the biggest US burst was only 15 megatons, and that was accidental, the designers expected 6-8 but we didn't realize the power of the first H-bombs. The biggest burst overall was by the Soviets, it yielded 50-60 megatons with the third stage replaced with lead to contain fallout. With the third stage installed it would have yielded at least 100 megatons.

Einhander Sn0m4n · Post by **Einhander Sn0m4n** » 2003-05-03 01:48pm

Sea Skimmer wrote:Yes that would be the kind of surface effect I'm looking for. I highly doubt anyone actually has the formal or rules of thumb I'm looking for, if they exist. But it's seems worth a shot.

I would love to get my hands on the formulas that would allow me to scale the sedan Test's 100kt to 400MT. No, I don't think it's a simple matter of multiplying the crater dimensions by four hundred thousand

Admiral Valdemar · Post by **Admiral Valdemar** » 2003-05-03 01:50pm

Einhander Sn0m4n wrote:
Sea Skimmer wrote:Yes that would be the kind of surface effect I'm looking for. I highly doubt anyone actually has the formal or rules of thumb I'm looking for, if they exist. But it's seems worth a shot.
I would love to get my hands on the formulas that would allow me to scale the sedan Test's 100kt to 400MT. No, I don't think it's a simple matter of multiplying the crater dimensions by four hundred thousand

Well remember, when you double the nuke power rating you don't double the blast radius or damage, but I'm sure there are probably some good formulas around somewhere.

Maybe USENET will have someone who figured this out.

Post by **Sea Skimmer** » 2003-05-03 01:52pm

Nuclear effects scale at the following rates. However I'm not sure that they hold true for subterranean bursts, since there's material in all directions to soak up energy.

Thermal: Y^0.41
Blast: Y^0.33
Radiation: Y^0.19

Admiral Valdemar · Post by **Admiral Valdemar** » 2003-05-03 02:01pm

Link.

No idea if this is that useful, but it seems to have some info. on nuclear testing and crater damage.

I'll a keep digging.

Burak Gazan · Post by **Burak Gazan** » 2003-05-03 02:10pm

The largest underground US shot was Canniken (sp?) in Alaska , Nov 1971 -- yield was around 5MT. Not certain how deep it was, but it obviously contained the fireball. If I remember correctly, shaft was drilled into solid rock, maybe 2 miles (3-4km?) down?
Still looking

Admiral Valdemar · Post by **Admiral Valdemar** » 2003-05-03 02:15pm

Burak Gazan wrote:The largest underground US shot was Canniken (sp?) in Alaska , Nov 1971 -- yield was around 5MT. Not certain how deep it was, but it obviously contained the fireball. If I remember correctly, shaft was drilled into solid rock, maybe 2 miles (3-4km?) down?
Still looking

With such weapons the heat isn't really the problem, it's the fallout you have to worry about. A large nuke of several MTs can make one big fireball, but the heat is easily dissipated, radiation is not.

Post by **Sea Skimmer** » 2003-05-03 02:15pm

Admiral Valdemar wrote:Link.

No idea if this is that useful, but it seems to have some info. on nuclear testing and crater damage.

I'll a keep digging.

Seems to be all for above surface busts, but its defiantly useful. If not for this question, then for some other things I need to work out. Using the formals I have I can scale these data sets to whatever yield I need for realistic effects in my writing.

All help is appreciated.

Burak Gazan · Post by **Burak Gazan** » 2003-05-03 02:25pm

Got something:

http://www.fas.org/faspir/2001/v54n1/weapons.htm#note2

Now, subject to review, if I follow that formula, it gives a depth needed of approx 20,000 feet. Sounds kinda low for 400MT, but this gets into some pretty advanced math

Admiral Valdemar · Post by **Admiral Valdemar** » 2003-05-03 02:29pm

Burak Gazan wrote:Got something:

http://www.fas.org/faspir/2001/v54n1/weapons.htm#note2

Now, subject to review, if I follow that formula, it gives a depth needed of approx 20,000 feet. Sounds kinda low for 400MT, but this gets into some pretty advanced math

Well try digging a 20,000 foot deep hole and tell me that's low.

Burak Gazan · Post by **Burak Gazan** » 2003-05-03 02:32pm

Hey, thats just the hole; now, plant the device and seal it to try and prevent escape of radiation and "contain" the blast.

Now, we need to find how big a cavity this would vaporize

Post by **Sea Skimmer** » 2003-05-03 02:36pm

Looks like your correct, but I'm pretty sure that number is for total containment. With FAS's quality of politics mixed information and heavy slant against the weapons the article is talking about I'd be pretty sure of it. But its still useful information as it gives a upper limit. And the depth is such that I could have my weapon achieve it. That’s not idea, I'd greatly prefer only partial containment but it isn't key to any storyline.

Post by **Sea Skimmer** » 2003-05-03 02:40pm

Burak Gazan wrote:

Hey, thats just the hole; now, plant the device and seal it to try and prevent escape of radiation and "contain" the blast.

Now, we need to find how big a cavity this would vaporize

Containing radiation isn't a goal. I just don't want to worry about the fireball blinding every one within a couple hundred kilometers while limiting how far I bend reaility to let this thing work. As for the delivery system, its a big sci tech missile. Now any real material would melt digging down to the needed depths or even a fraction of them. But my solution is fairly simple

[1] Use a sci tech material for the casing
[2] Have a sustainer engine keep pushing it down after it hits the ground. That way all the energy needed doesn't have to be built up before hand